As a player, he won six Hungarian league championships with Budapest-based side MTK in the 1920s and regularly appeared for Hungary national football team.

Opata immediately established himself as a regular member of a star-studded squad along with teammates György Orth, József Braun and Imre Schlosser.

However, in their second round match Hungary suffered a sensational 0–3 defeat to underdogs Egypt which ended their hopes of winning Olympic medals.

Opata continued to be a regular member of the national team until for the next three years and was used by managers in all positions in the attacking line, appearing in a total of 17 matches and scoring 6 goals between 1922 and 1927.

In the so-called "Mighty Magyars" era of the early 1950s Opata was a member of the national team's coaching staff and in that capacity helped them win gold in the 1952 Summer Olympics.